Feed network

Details Feed network Feed network

2002-09-23

2004-09-07

Phan, Tho G. (Department: 2821)

Communications: radio wave antennas

Antennas

Spiral or helical type

C343S850000, C343S853000

Reexamination Certificate

active

06788272

ABSTRACT:

FIELD OF THE INVENTION
The present invention relates to an antenna feed network, and to an antenna such as a quadrifilar helix antenna incorporating such a feed network.
DESCRIPTION OF THE RELATED ART
A conventional feed network is shown in U.S. Pat. No. 5,541,617. A hybrid junction power divider feed circuit provides 0 to 180° phase shift. The radiating elements are connected to the feed circuit in pairs. The second element of each pair is shorter than the first element by a predetermined distance to provide a phase quadrature between them.
An alternative feed network is shown in
FIG. 5
of U.S. Pat. No. 5,955,997. The feed network is a non-isolating inline power splitter with an excess quarter-wavelength line in one output arm to generate the required 90° phase differentials.
A helical antenna is described in U.S. Pat. No. 6,172,656. In the embodiment of
FIG. 3
, the antenna arms are aperture fed by a drive circuit including a 180° hybrid coupler and two 90° hybrid couplers.
BRIEF DESCRIPTION OF EXEMPLARY EMBODIMENT
An exemplary embodiment of the invention provides an antenna feed network including:
a 180° hybrid coupler having a feed port, a 0° port, and a 180° port having an approximately 180° phase difference with the 0° port;
a first antenna port coupled to the 0° port;
a second antenna port coupled to the 0° port via a respective phased line, the second antenna port having an approximately 90° phase difference with the first antenna port;
a third antenna port coupled to the 180° port; and
a fourth antenna port coupled to the 180° port via a respective phased line, the fourth antenna port having an approximately 90° phase difference with the third antenna port.
It will be appreciated by a skilled person that the actual phase difference between the ports may differ slightly from the approximate values given above: in practice the phase difference may vary by up to 2%, or even in extreme cases up to 5% either side of the approximate value.
The feed network may be incorporated into an antenna in which a radiating element is coupled to each antenna port. A preferred application for the antenna is for receiving satellite Global Positioning System (GPS) signals.


REFERENCES:
patent: 5134422 (1992-07-01), Auriol
patent: 5198831 (1993-03-01), Burrell et al.
patent: 5349365 (1994-09-01), Ow et al.
patent: 5541617 (1996-07-01), Connolly et al.
patent: 5581268 (1996-12-01), Hirshfield
patent: 5786793 (1998-07-01), Maeda et al.
patent: 5872549 (1999-02-01), Huynh et al.
patent: 5955997 (1999-09-01), Ho et al.
patent: 5986616 (1999-11-01), Edvardsson
patent: 6011524 (2000-01-01), Jervis
patent: 6172656 (2001-01-01), Ohwada et al.
patent: 6320480 (2001-11-01), Kintis et al.

Affiliated with

Also associated with

Rating

Feed network does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Feed network, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Feed network will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3205532